Hypodermic syringes of known constructions employ a cylindrical barrel having a needle covered with an end cap. To use the syringe, the end cap is slipped off and the needle inserted into a patient to inject a fluid with a plunger or aspirate blood and other bodily fluids back into the syringe. After use the cap is replaced on the needle and both are discarded. A not infrequent problem with these devices however is the accidental puncture of the medical attendant using the syringe when replacing the cap. Often this occurs when the cap is being replaced and requires care to be sure the needle is properly inserted in the cap. If a distraction occurs the user can easily miss the entrance to the cap and puncture the finger or some other portion of the hand or arm. Since these needles are frequently used on patients that have serious blood borne diseases the contamination can be transferred to the medical attendant infecting them with the disease of the patient. This can have serious side affects if the disease is an infectious disease such as hepatitis, aids or other infectious diseases. It would be advantageous if some method could be provided for replacement of a protective cap on the needle while keeping the extremities and particularly the hands well away from the needle point.
Examples of caps for hypodermic syringe needles are shown in U.S. Pat. Nos. 2,408,323, 2,571,653, 3,073,306, 3,527,216, 3,890,971, 4,355,822, 4,373,526 and 4,425,120, all show a slideable shield to protect the needle on a hypodermic syringe. Each of these devices is quite complex and requires special manufacture of the hypodermic syringe. To date none of these devices appear to be on the market for reasons which should be apparent from an examination of the patents. U.S. Pat. Nos. 3,825,003, 3,976,069 and 4,249,530 all show caps which act as needle guards. None of the devices appear to show a simple, easy to manufacture protective cap which can be used with existing syringes and needles.